class Solution {
public:
    int getSum(int a, int b) {
        //10101011
        //11001010
        int ret=0;
        while(b!=0)
        {
           ret=a^b; 
           unsigned int carry=(unsigned int)(a&b)<<1;
           a=ret;
           b=carry;
        }
        return a;
    }
};

